unix: implement recvmsgRaw and sendmsgN on aix

This allows using RecvmsgBuffers and SendmsgBuffers on aix in x/net. For golang/go#54099 Change-Id: Ib21c59244c9d74b826f4fc8ba3314e3602fd9a8a Reviewed-on: https://go-review.googlesource.com/c/sys/+/419396 Reviewed-by: Cherry Mui <[email protected]> Reviewed-by: Ian Lance Taylor <[email protected]> Run-TryBot: Tobias Klauser <[email protected]> Auto-Submit: Tobias Klauser <[email protected]> TryBot-Result: Gopher Robot <[email protected]>
golang · Jul 28, 2022 · 3c1f352 · 3c1f352
1 parent e65921a
commit 3c1f352
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Showing 2 changed files with 53 additions and 8 deletions.
diff --git a/unix/syscall_aix.go b/unix/syscall_aix.go
@@ -218,13 +218,62 @@ func Accept(fd int) (nfd int, sa Sockaddr, err error) {
 }
 
 func recvmsgRaw(fd int, iov []Iovec, oob []byte, flags int, rsa *RawSockaddrAny) (n, oobn int, recvflags int, err error) {
-	// Recvmsg not implemented on AIX
-	return -1, -1, -1, ENOSYS
+	var msg Msghdr
+	msg.Name = (*byte)(unsafe.Pointer(rsa))
+	msg.Namelen = uint32(SizeofSockaddrAny)
+	var dummy byte
+	if len(oob) > 0 {
+		// receive at least one normal byte
+		if emptyIovecs(iov) {
+			var iova [1]Iovec
+			iova[0].Base = &dummy
+			iova[0].SetLen(1)
+			iov = iova[:]
+		}
+		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
+		msg.SetControllen(len(oob))
+	}
+	if len(iov) > 0 {
+		msg.Iov = &iov[0]
+		msg.SetIovlen(len(iov))
+	}
+	if n, err = recvmsg(fd, &msg, flags); n == -1 {
+		return
+	}
+	oobn = int(msg.Controllen)
+	recvflags = int(msg.Flags)
+	return
 }
 
 func sendmsgN(fd int, iov []Iovec, oob []byte, ptr unsafe.Pointer, salen _Socklen, flags int) (n int, err error) {
-	// SendmsgN not implemented on AIX
-	return -1, ENOSYS
+	var msg Msghdr
+	msg.Name = (*byte)(unsafe.Pointer(ptr))
+	msg.Namelen = uint32(salen)
+	var dummy byte
+	var empty bool
+	if len(oob) > 0 {
+		// send at least one normal byte
+		empty := emptyIovecs(iov)
+		if empty {
+			var iova [1]Iovec
+			iova[0].Base = &dummy
+			iova[0].SetLen(1)
+			iov = iova[:]
+		}
+		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
+		msg.SetControllen(len(oob))
+	}
+	if len(iov) > 0 {
+		msg.Iov = &iov[0]
+		msg.SetIovlen(len(iov))
+	}
+	if n, err = sendmsg(fd, &msg, flags); err != nil {
+		return 0, err
+	}
+	if len(oob) > 0 && empty {
+		n = 0
+	}
+	return n, nil
 }
 
 func anyToSockaddr(fd int, rsa *RawSockaddrAny) (Sockaddr, error) {

diff --git a/unix/syscall_unix_test.go b/unix/syscall_unix_test.go
@@ -957,10 +957,6 @@ func TestSend(t *testing.T) {
 }
 
 func TestSendmsgBuffers(t *testing.T) {
-	if runtime.GOOS == "aix" {
-		t.Skipf("SendmsgBuffers not supported on %s", runtime.GOOS)
-	}
-
 	fds, err := unix.Socketpair(unix.AF_LOCAL, unix.SOCK_STREAM, 0)
 	if err != nil {
 		t.Fatal(err)